본 연구는 생후 12개월령의 염소를 사용하여 앞다리, 뒷 다리, 등심 및 갈비 부위로 분할하여 in vitro 소화실험을 통해 부위별 단백질 가수분해도 및 아미노산 조성을 조사 하였다. 이 때, 소고기 및 돼지고기의 분할육을 이용하여 염소고기와 비교, 분석하였다. 염소고기 분할육 중 뒷다리 (8.32%) 및 갈비(8.32%)가 가장 높게 단백질 가수분해도가 나타났으며, 염소고기의 갈비 부위는 갈비 분할육 중 가장 높은 단백질 가수분해율을 보였던 돼지고기(8.57%)와 유의 차가 없었다 (P>0.05). In vitro 소화 전에는 염소고기 분할 육 중 등심에서 글리신(11.03%)이, 앞다리에서 글루타민 (53.44%)이 다른 고기 종류 및 분할육들에 비해 유의적으 로 높은 비율로 포함된 것이 확인되었다(P<0.05). In vitro 소화 후에는 염소고기 갈비 부위에서 라이신(17.54%)이 가 장 높은 비율로 포함된 것으로 확인되었으며, 소 갈비 부 위보다 유의적으로 높았다(P<0.05). 본 연구는 염소고기 분 할육의 단백질 가수분해도 및 아미노산 조성을 제공하며 단백질 소화양상 및 생체 이용률을 평가하기 위한 기초 자 료로써 활용되어질 수 있을 것으로 사료된다.

본 연구에서는 유화제를 사용하지 않고 초단파 산분해법을 이용해 우리나라에서생산된 참기름의 중금속을 측정하고자 하였다. ICP-MS를 통해 12개의 참기름 시료에 오염된 카드뮴, 납, 비소의 3종 중금속을 분석하였다. 분석법의 검증 결과 카드뮴, 납, 비소 모두 직선성((r2)이 0.99 이상이며 RSD는 4% 이하였다. 또한, 분석법의 정확성 및 효율성 측정을 위해 중금속 10 μg/g 과 100 μg/g 을 첨가한시료를 분석한 결과, 회수율이 카드뮴 98.5-101.6%, 납 100.3-101.3%, 비소 102.1-111.2%로 우수하게 나타났다. 본 분석법을 이용하여 분석한 참기름 시료의 중금속 함량은 카드뮴 불검출~0.109 μg/g, 납 0.014~0.200 μg/g, 비소 0.014~0.125 μg/g 이었다. 따라서, 중금속 오염지역에서 생산된 참깨 및 이를 이용한 가공품의 경우 섭취에 주의할 필요가있다.

원자력 발전소에서 발생하는 고체 방사성 폐기물인 이온교환수지, 제올라이트, 활성탄 및 슬러지 에 포함된 성분 원소 분석을 위한 산분해 조건을 확립하였다. 방사성 폐기물의 분해 에는 흔합산을 이용한 밀폐형 극초단파 산분해법을 사용하였으며, 제안한 방법에 따른 산분해 후의 용액은 맑고 색이 없는 투명한 상태임을 확인할 수 있었다. 또한, 산분해 과정을 거친 각각의 용액 시료는 ICP-AES와 AAS를 사용하여 분석하였고, 모의 방사성 폐기물에 첨가한 5종의 금속 원소들은 이상의 높은 회수율을 보여주었다. 화학적 특성을 고려하여 제안된 산분해 조건에 의해 용액화된 중저준위 방사성 폐기물의 성분 원소 분석은 최적의 유리화 기술 개발을 위한 기초 자료로 유용하게 사용될 수 있을 것으로 판단된다.

The effect of natural foods, utilizing the extracts or juices of teas(Green tea; Camellia sinesis, Du' thong; Eucommia ulmoides Oliver), medicinal plants(Eu sung cho; Houttuynia cordata Thunb, Sam back cho; Saurus Chinensis, Baek hwa sa seal cho; Oldenladia diffusa Roxb.) seaweeds(Laver; Porphyra tenera, Sea mustard; Undaria pinnatifida, Sea staghorn; Condium fragile) and vegetables(Sweet pepper; Capsicum annuum var. angulosum, Kale; Brassier oleracea var. acephala, Cucumber; Cucumis satiaus, Onion; Album cepa) and fruits(Tomato; Lycopericon esculentum, Maesil; Prunus mume, Plum; Prunus salicina and Grape; Vitis sppJon the inhibition of N-Nitrosodimethylamine(NDMA) formation was investigated from the various conditions. The inhibition effect was observed in vitro using the reaction fluids of pH 1.2, 4.2 and 6.0. )mom the teas and medicinal plants, there was a positive response of NDMA formation; however, from the seaweed extracts, there was a negative response of the inhibition effect of NDMA formation, and as the pH of reaction fluids and the amount of materials increase, the inhibition of NDMA formation was strengthened. The inhibition ratios by the level of pH are as follows: under pH 1.2 vegetable juice were 57.6 99.7% and fruits were 35.9 99.7%; under pH 4.2 vegetable juice were 55.0-97.5% and fruits were 21.3 96.8%. All of the materials observed has been proved and shown the inhibition effect of NDMA formation.

In this study, the inhibition of ammonia on anaerobic digestion of butyric acid was evaluated and the potential alleviating effects of such ammonia inhibition by the addition of magnetite particles were investigated. Independent anaerobic batch tests fed with butyric acid as a sole organic source were conducted in twenty 60-mL glass bottles with 10 different treatment conditions, comprising ammonia: 0.5, 2.0, 4.0, 6.0, and 7.0 g total ammonia nitrogen (TAN)/L and magnetite particles: 0 mM and 20 mM. The increase in ammonia concentration did not cause significant inhibition on methane yield; however, a significant inhibition on lag time and specific methane production rate was observed. The IC50 in the control treatments (without magnetite addition) was estimated as 6.2654 g TAN/L. A similar inhibition trend was observed in magnetite-added treatments; however, the inhibition effect by ammonia was significantly alleviated in lag time and specific methane production rate when compared to those in the control treatments. The lag time was shortened by 1.6–46.3%, specific methane production rate was improved by 6.0–69.0%. In the magnetite-added treatments, IC50 was estimated as 8.5361 g TAN/L. This study successfully demonstrated the potential of magnetite particles as an enhancer in anaerobic digestion of butyric acid under conditions of ammonia stress.

The present study investigated the effect of ammonia load on microbial communities in mesophilic anaerobic digestion of propionic acid. A laboratory-scale continuous anaerobic digester treating propionic acid as a sole organic substrate was operated under non-inhibitory condition and inhibitory conditions with ammonia (1.5 g and 3.5 g ammonia-N/L, respectively), and bacterial and archaeal communities in the steady states of each ammonia condition were analyzed using high-throughput sequencing. Thirteen bacterial families were detected as abundant bacterial groups in mesophilic anaerobic digestion of propionic acid. Increase in ammonia concentration resulted in significant shifts in microbial community structures. Syntorophobacter, Pelotomaculum, and Thermovigra were determined as the dominant groups of (potential) propionate oxidizing bacteria in the non-inhibitory condition, whereas Cryptanaerobacter and Aminobacterium were the dominant groups of (potential) propionate oxidizing bacteria in the ammonia-inhibitory condition. Methanoculleus and Methanosaeta were the dominant methanogens. Acetate-oxidation coupled with hydrogenotrophic methanogenesis might be enhanced with increases in the relative abundances of Methanoculleus and Tepidanaerobacter acetatoxydans under the ammonia-inhibitory condition. The results of the present study could be a valuable reference for microbial management of anaerobic digestion systems that are exposed to ammonia inhibition and propionic acid accumulation.

The quality standards of solid refuse fuel (SRF) define the values for 12 physico-chemical properties, including moisture, lower heating value, and metal compounds, according to Article 20 of the Enforcement Rules of the Act on Resource Saving and Recycling Promotion. These parameters are evaluated via various SRF Quality Test Methods, but problems related to the heavy metal content have been observed in the microwave acid digestion method. Therefore, these methods and their applicability need improvement. In this study, the appropriate testing conditions were derived by varying the parameters of microwave acid digestion, such as microwave power and pre-treatment time. The pre-treatment of SRF as a function of the microwave power revealed an incomplete decomposition of the sample at 600 W, and the heavy metal content analysis was difficult to perform under 9 mL of nitric acid and 3 mL of hydrochloric acid. The experiments with the reference materials under nitric acid at 600 W lasted 30 minutes, and 1,000 W for 20 or 30 minutes were considered optimal conditions. The results confirmed that a mixture of SRF and an acid would take about 20 minutes to reach 180 oC, requiring at least 30 minutes of pre-treatment. The accuracy was within 30% of the standard deviation, with a precision of 70 ~ 130% of the heavy metal recovery rate. By applying these conditions to SRF, the results for each condition were not significantly different and the heavy metal standards for As, Pb, Cd, and Cr were satisfied.

This study has been conducted to investigate biodegradation characteristics and optimum mixing ratio for co-digestion with thermophilic acid-fermented food waste and sewage sludge using batch anaerobic digester. As the basis operating conditions for anaerobic digestion, the reaction temperature was controlled 35±1℃ and stirrer was set 70rpm. Thermophilic acid-fermented food waste and sewage sludge were mixed at the ratio of 10:0, 7:3, 5:5, 3:7, 0:10 and 5;5(food waste : sewage sludge) as the influent substrates. In results of co-digestion according to mixing ratio of thermophilic fermented food wastes and sewage sludge in batch mesophilic anaerobic digestion reactor, 385mL CH4/g VSadded of methane production rate at 1:1 mixing ratio was more than that of any other mixing ratios. Compared with 293mL CH4/g VSadded of methane production rate at 1:1 mixing ratio of food wastes and sewage sludge, pretreatment of food wastes by thermophilic acid fermentation was more effective in co-digestion with sewage sludge.